This study investigated the effects of performance feedback and EMG biofeedback on perceptions of the "self" (i.e., self-esteem, self-control, self-efficacy, and locus of control) as well as on a self-control behavior (study skills) the subjects performed outside the laboratory. Forty-seven college students were randomly assigned to one of four groups in a 2(high and low success feedback) x 2(true and false EMG biofeedback) factorial experiment with repeated measures. All of the participants received four sessions of EMG biofeedback, and later they were asked to self-monitor their study habits for 2 weeks. Results showed that the self-esteem measure and perceptions of study skills improvement were differentially affected by success feedback but unrelated to the true or false EMG manipulation. Shifts toward an internal locus of control and perceptions of improved self-control were also noted, but they were independent of the subjects' group membership. Implication of the results are briefly discussed.